In connection with motor vehicles, different types of bearings may be utilized for supporting the wheels on their respective wheel axles. Where, for instance, heavier commercial vehicles are concerned, the rear wheels may be carried on bearings on the rear axle of the vehicle by means of two roller bearings mounted next to each other. According to the prior art, these roller bearings are typically arranged side by side so that they bear on each other. The roller bearings are kept together in an unmounted condition by means of a bearing ring, which is substantially annular, and which is mounted on the rear axle.
Within the internal surfaces of the inner races of the bearings, i.e. on the surfaces which constitute the inside of the inner races and the outside of the rear axle itself, a thin layer of oil must be supplied for the purpose of protecting the bearings and the rear axle from corrosion. This oil is successively supplied through the interior of the rear axle and is conducted in between the peripheral surface of the rear axle and the inner side of each respective roller bearing.
Furthermore, according to the prior art, the roller bearings themselves are lubricated by bearing grease. This bearing grease is applied when assembling the roller bearings and is retained on the bearing rollers and bearing races by means of seals.
A problem which occurs in connection with these previously known rear axle assemblies is related to the fact that a small gap or interval is formed between the inner races of the two roller bearings. This, in turn, creates the risk that the oil layer between the insides of the roller bearings and the rear axle can penetrate through this gap during operation of the vehicle. This may occur as a result of the small movements which always arise in the rear axle during operation of the vehicle, in which case the gap between the inner races cannot be kept completely sealed.
The fact that oil leaks out in a radial direction through the gap between the two bearings entails certain disadvantages. On the one hand, the oil is harmful to the bearing grease of the roller bearings. On the other hand, the oil may contain impurities in the form of small particles which may be deposited on the bearings, something which naturally is a disadvantage. A further disadvantage with such leakage is that the surf ace of the rear axle and the internal surfaces of the inner races risk running dry, which in turn creates a risk of contact corrosion between the bearings and the rear axle. This means, for instance, that wheel changes are rendered considerably more difficult.
In light of the above-mentioned problems, there is a need for seals, which can seal the gap between the inner races. However, this presents further difficulties, among other things resulting from the fact that the area around the gap becomes inaccessible once the bearings have been pressed into position. This results in difficulties when mounting the bearings and seals for such bearings.